Box strapping machine



Dec. 5, 1939. F, M BYL 2,182,221

BOX STRAPPING MACHINE Filed May 10, 1937 2 Sheets-Sheet l A TTORNE Y5 Patented Dec. 5, 1939 UNITED STATES FATEN'T FFiQil 17 Claims.

The present invention relates to improvements in box strapping machines and its principal object is to provide a machine of the character described which is simple in construction, speedy in operation, economic in use and which performs its operation while the box remains stationary so as to prevent any shaking or jarring of any perishables that may be contained in the box.

More particularly my invention is intended principally for use in connection with boxes used in fruit packing houses. Boxes of this kind, in addition to being nailed, are usually strapped near their outer ends, and this operation when done by hand or machinery available at the present time is quite laborious and usually involves the turning of the box which is detrimental to the fruit or vegetables contained therein.

It is proposed in the present invention to provide a box strapping machine in which a wire is strapped around the end of the box while the latter is in a position of rest.

It is further proposed to provide a machine of the character described in which both ends of the box may be strapped at the same time for doubling the speed of the operation.

It is further proposed to provide a novel mechanical movement for accomplishing the objects set forth.

It is further proposed to arrange the box strapping means in such a manner that the machine may be adjusted readily for difierent sizes of boxes by the mere exchange of an easily accessible guide plate.

Further objects and advantages of my invention will appear as the specification proceeds.

The preferred form of my invention is illustrated in the accompanying drawings in which Figure 1 shows a side view of my box strapping 'machine;

Figure 2 a vertical section taken along line 2-2 of Figure 1;

Figure 3 a plan view of a portion of the machine as'seen from line 3-4] of Figure 1;

Figure 4: an enlarged detail view of a cam plate -71 used in my machine;

Figure 5 a vertical section similar to that of Figure 2. but showing certain parts in a different position;

Figure 6 a vertical section through a wire feed so mechanism;

Figure 7 a plan view of the wire feed mechanism;

Figure 3 a perspective detail view of a wire holder used in my machine;

Figure 9 a perspective view showing one end of a box to which the wire has been applied so as to be ready for the final twisting or tying operation, and

Figure 10 a section taken along line lit-l8 of Figure 1.

While I have shown only the preferred form of my invention I wish to have it understood that various changes or modifications may be made within the scope of the claims hereto attached without departing from the spirit of the invention.

Referring to the drawings in detail, I provide a platform l, suitably supported by means not shown, the platform comprising a front section 2 having a plurality of balls 3 partly imbedded therein and a main section 4 which has rollers 5 secured to the edge thereof, the top edges of the rollers being in a plane with the top faces of the balls.

The box Hi to be strapped is placed by the operator or by suitable machinery, upon the front section 2 of the platform and is pushedalong on the balls and the rollers until it reaches the stops 6, when it is improper position for the strapping operation. When thus positioned, both ends of the box project beyond the rollers 52, as shown With respect to one end in Figure 2. Throughout this description it should be understood that the means shown and described for strapping one end of the box may be readily duplicated" for i strap-ping both ends at the same time.

The strapping mechanism is supported by a vertical plate which latter is arranged parallel and in spaced relation to the edge of the platform or the rollers 5, as shown in Figure 2, and is supported by any suitable means not shown in the drawings. It carries upon its outer face (see Figure 1) a wire feeding mechanism and upon its inner face a wire attaching mechanism (see particularly Figures 2. and 5) and a wire twisting mechanism, which latter does not form any part of the present invention and therefore is not shown or described.

The wire feeding mechanism is shown in its principal features in Figure 1 and in detail features in Figures 3, 4, 6, '7, and 10. It comprises essentially an extensible guide rod H pivoted to the plate 7 as at I2 and carrying at its upper end a feed spout l3, an operating mechanism M for the guide rod, and a guide plate 15.

The guide rod H is made in two parts iii and Il, the latter being slidable longitudinally in the former and projecting beyond the upper end thereof. In its upper end part I! carries the wire spout l3 (see Figure 6) which is mounted in bearings 18 adapted to be adjusted by a nut 19. The spout has a disc 20 secured upon its outer end by means of a nut 21 and this disc has a flat section 22 in its circumference. A spring-pressed plunger 23 bearing on the fiat section has a tendency to hold the disc and the spout against rotation when the spout occupies a horizontal position as in Figure 1. The plunger, however, yields to permit rotary motion when sufficient force is applied.

A wire 25 is passed from a spool (not shown) through suitable stretching means (not shown) and through a positive arresting means 26 into a guide tube 21 and thence through an aperture 28 in the spout for feeding from the turned discharge end of the latter. The spout is intended to travel around the projecting end of the box If), starting along the bottom and following the dotted line shown in Figure 1. While it travels it feeds the wire around the box and automatically turns in its bearings as it passes each corner of the box.

To cause the feed spout to follow the course outlined I provide the operating mechanism M in combination with the guide plate 15. The operating mechanism comprises a lever 30 pivoted to the plate I as at 31, the pivotbeing spaced from the upper end of the guide rod H by a considerable distance as shown in the drawings. One arm 32 of the lever is connected to part It of the guide rod l l by means of a link 33 and the other arm of the lever is connected to the upper end of part H of the guide rod by means of a link 35.

The link 33 is made extensible and consists of a cylinder 35 pivoted to the arm 32 as at 31, a piston 38 movable in the cylinder and a piston rod 39 pivoted to part 16 of the guide rod as at M3. The link may thus be contracted and ex tended by feeding a pressure medium on one side of the piston While exhausting from the other side, for which purpose a suitable'four way valve All of conventional type may be used. It will be noted that when pressure is admitted for extending link 33 it has a tendency to move part 16 of guide rod H to the left (as viewed in Figure 1) and part I! of the guide rod in an upward direction, while contraction of link 33 has a tendency to pull part 56 of the guide rod to the right and part H in a downward direction;

For guiding the guide rod H to cause the wire feed spout to follow the desired course, I provide the guide plate l5 which is removably and exchangeably secured to the plate 1' behind the guide rod H. The guide plate is formed with a cam groove 4L2 which is used for guiding a pin i3 projecting from part ll of the guide rod H through a longitudinal slot 44 in part 16 into the groove, and the latter is formed to guide the member ll for causing the feed spout to take the desired path around the box.

The shape of the cam groove does not exactly register with that of the box and is preferably made as shown in Figure 4. The bottom portion 55 is preferably formed ona slight curve which has a tendency to smooth out the angle between it and the sides Mi and M of the groove, which are made slightly slanting for the same purpose. This facilitates travel of the pin 43 around the lower corners. v v

The upper portion 68 of the groove may be slightly curved in an opposite direction, as it is important that near the juncture indicated at it the groove be drawn substantially to the arc of a circle having the pivot l2 of the guide rod for its center so that there will be no slack in the wire fed while the spout passes from point 50 indicated in Figure l to the nearest corner of the box. It should be understood that sufiicient resistance is provided to the feeding of the wire to prevent any slack as long as the spout keeps the wire already fed in a taut condition.

An initial fastening means for the wire is provided in the post 5| which is shown in detail in Figure 8 and which is circular in cross-section and terminates, in its upper end, in a semioylindrical extension 52 having a longitudinal slot dividing the same in a pair of spaced prongs '53 and 54, the spacing between the prongs corresponding substantially to the thickness of the wire to be used.

This post 5| is mounted rearwardly of the plate '5 in a bracket 55 and with freedom of sliding motion in a vertical direction. A spring 56 hearing on a pin 51 projecting from the post normally holds the latter in its uppermost position, that is with the prongs almost touching the box. The lower end of the post is received in a cylindrical socket 58 at the upper end of a piston rod 59 which latter projects from a piston 60 movable in a cylinder 6!. Movement may be imparted to the piston in either direction by a pressure medium under control of a suitable combination intake and exhaust Valve indicated at 6!.

The socket 58 has a pin 52 riding in a spiral groove 63 of the post for turning the latter through an angle of 180 degrees when the socket moves endwise, the latter being held against turning movement by a pin 54 riding in a vertical groove 65 in the supporting bracket 55.

The post is thus mounted with freedom of turning movement between the positions shown in Figures 2 and 5 respectively. In the position shown in Figure 2 the two prongs clear the path of the wire feed spout so that the latter may pass freely, while in the position shown in Figure 5 the slot between the prongs lies directly in the path of the wire and the prongs are used as a point of attachment for the wire at the begining of each strapping operation.

The wire is fastened to the post in the following manner: Figure 1 shows the operating parts substantially at the end of a wrapping operation. During the operation just finished the end of the wire was attached to the post, the spout guided around the box and past the post to parallel itself on the left side of the post so that at the moment indicated there are two strands of wire in substantially parallel and adjacent relation between the post and the spout, ready for a tying or twisting operation not disclosed in the present application. The post, during the latter part of the operation, was in the position shown in Figure 2 so as to allow the spout to pass. The

' pin 43 at this time is in the left hand lower corner of the cam groove, substantially as shown in both Figures 1 and 4.

The next operation would be the twisting of the parallel strands between the post and the spout and the cutting of the wire at the post and at the spout. But for the starting of the next operation it is desirable that a portion of wire remains projecting from the spout, and to take care of this, the pin 43, instead of stopping at the lower left hand corner of the cam groove, is permitted to continue its travel into a dead en continuation 65' of the groove. I

This dead end is normally closed by a pawl 67 pivoted to the plate l5 as at 58, but the pawl is operated, at this particular time, by any suitable means, to open the dead end and close the bottom end of the upright portion 45 of the cam groove so that the pin 43 may enter the dead end. The movement of the pawl 61 is transmitted, through the link 69, the lever 10 and a spring- -ressed rod ii to the wire arresting means 26 which is operated to arrest further feeding of the wire so that the extended travel of the pin 43 into the dead end effects a tightening of the entire wire around the box.

While the pin 43 moves toward the limit of the dead end groove, the twisting and cutting action takes place, with the result that the wire is tightly fitted around the box and that a piece of wire remains projecting from the spout.

For the beginning of the next operation the post 55 is turned, by operation of the piston 6! through an angle of 180 degrees so that the slot between the prongs lies now in alinernent with the piece of wire projecting from the spout. The latter is now made to travel backward, by operation of the piston 38, so as to cause the pin 43 to re-enter from the dead end into the bottom portion d5 of the cam groove and to cause the end of the wire projecting from the spout to enter the slot between the prongs which latter preferably rounded at the point of entry, as at ?2, to facilitate the engagement. As soon as the wire has entered, the post is turned to bind the end of the wire and to clear the path for the spout when it passes the post on its return from the next trip around the box.

While the pin l3 moves backward in the bottom groove for connecting the wire to the post, position of the pawl it? is changed to close dead end and to open the vertical groove 45. The backward movement of the pin 43 in the groove 55 is limited by a spring-operated pawl "l3 which prevents further backward movement but allows movement in the opposite direction. Two similar spring-operated pawls M and '85 are provided at opposite corners of the cam groove to positively guide the pin 43 into the proper direction at these points.

The bracket 55 has a fixed collar l6 surrounding the upper portion of the post 5i and this collar has a slanting upper end as shown at 5?. As has been previously pointed out, the piston in addition to effecting a turning movement of the post through the pin G2, may also be used for retracting the post against the opposition of the spring 5%, and this retractive movement is used, between any two operations, for clearing the post of the remnant of wire-adhering thereto from the previous operation.

The entire operation may be described as follows: At the start of the operation, the guide pin it may be considered as being in the extreme end of the dead end 65, with the pawl 61 in the dotted line position of Figure 4, a piece of wire projecting from the end of the spout l3, as shown in Figure the spout being yieldingly held in horizontal position by the plunger 23.. and the post turned to bring the slot into alinement with the projecting wire.

A pressure medium is now admitted into the cylinder on the left side as viewed in Figure 1, whereby the guide rod with the spout is moved to the right, the pin 13 riding out of the dead end into the bottom portion 35 of the groove until it is stopped by the pawl 73. During this movement of the spout the free end of the projecting wire is introduced between the prongs of the post (see Figure 7) which. at this time,

occupies the position indicated in Figure 5.

Next a pressure medium is admitted into the cylinder 6!, underneath the piston 60, whereby the latter is moved upward, causing the pin 62 to ride upward in the spiral groove 63 and to turn the post by 180 degrees, that is, into the position shown in Figures 2 and. 3, whereby the wire is substantially locked to the post.

In timed relation to this last movement the pawl 6'! is moved into the full line position of Figure 4 which also causes the feed arresting means 2%: to be released so that the wire is now free to feed through the spout.

Now the pressure medium is admitted into the cylinder 36 on the right side of the piston 38 (see Figure 1) whereby the guide rod is made to swing to the left due to the action of the link 33, until the pin 43 strikes the pawl 61. At this time further progress to the left is prevented and further extension of the link 33 causes the lever 30 to swing about its pivot and to exert upward pressure on the link 35 which causes the upper part i? of the guide rod 1 I to slide upward, the pin 33 riding in the groove 46 and causing the spout which turns on its bearings as it turns around the corner of the box, to follow the dotted indicated in Figure 1, until it reaches the point 59. At that time the pin 43 has reached the top of the groove 48 and has passed the pawl I5 which prevents a return movement. The spout, of course, keeps feeding out the wire as it advances.

Next the pressure medium is applied to the left hand side of piston 38 (Figure l) causing the link 33 to contract and to pull the guide rod to the right. causing the spout to pass over the top of the box to the right hand side until the pin d3 reaches the right end of the upper groove 48. Further contraction of the link causes the lever Jill to swing about its pivot and to exert downward pull on the part I? of the guide rod it so as to cause the spout to travel downward along the right side of the box as shown in dotted lines in Figure 1. travels downward in the groove section M until it passes the pawl M.

It should be noted that although the spout follows the dotted line path which is longer than the circumference of the box, the length of wire actually fed through the spout is exactly that called for by the dimensions of the box since there is enough resistance to the wire to stop feeding when no wire is required. Thus no wire will be fed while the spout moves from point Fail to the nearest edge of the box and the feed is slowed down while the spout moves down the right side of the box.

After the pin 43 has reached the lower right hand corner of the cam groove, the pressure. medium in the cylinder 36 is again changed to urge the guide rod H to the left. The pin 61% freely passes the pawl l3 and as it approaches the left end of the bottom groove pawl ill swings into the dotted line position of Figure 4, tightening the arresting means. 25 upon the wire and permitting the pin 43 to enter the dead end of the groove. As it passes to the limit of the dead end groove it effects a final tightening of the wire that has been fed around the box and as a result of this operation two strands of the wire are arranged in parallel and adjacent relation between the post and the spout, substantially as shown in the perspective view of Figure 9.

These two strands are now twisted together by means of a conventional twisting mechanism not shown in the drawings, which latteralso cuts the The pin (l3 in the mean time wire on opposite sides of the twist, that is, at a point adjacent the post and at a point spaced from the end of the spout so as to leave a short piece of wire projecting from the spout for the beginning of the next operation.

A pressure medium is now admitted above the piston 60 in the cylinder 6! for pushing the piston clear down, whereby'the post is turned to its initial position with the slot in line with the piece of wire projecting from the spout. This operation also causes the post to momentarily retract below the member I! for ejecting the remnant of the wire still adhering to the post. The spring 56 returns the post to operative position when the pressure is released so that the different parts are now in position for the next operation.

The finished box is now removed, preferably by withdrawing the stops 6, which may be made retractible, and a new box is substituted.

It will be noted that the path described by the wire feeding spout is determined by the shape of the groove in the plate l5 and that the apparatus may be easily changed to strap a box of different shape by the mere substitution of a different cam plate.

I claim:

1. In combination, an extensible member, means for swingably supporting one end thereof, means for. moving the member to cause its free end to describe the path of a loop, the latter means comprising means for alternating swinging effects with extension and contraction effects and guide means controlling the duration of the eifects, and means for feeding a tying strand from said free end during the describing of the loop.

2. In a box strapping machine, means for supporting a box with one end projecting beyond the support, a swingably supported extensible member movable across the face of the projecting box end in a plane parallel thereto, means for guiding the free end of the extensible member in the path of a loop corresponding substantially to the shape of the box and a feeder for a strand of wire revolvably mounted in the free end of the member and projecting over the box so as to feed the wire therearound.

3. In a box strapping machine, a wire holder having means for securing a wire to one end thereof, means for retracting the holder and a guard adjacent the holderfor pushing off the wire when the holder is retracted 4. In a box strapping machine, a wire holder comprising a cylinder, a plunger movable there-in, spring means causing the plunger to normally project beyond the cylinder, the projecting end being formed with an endwise slot for receiving a wire therein, a member movable longitudinally on the plunger and a. connection between the member and the plunger causing the plunger to turn for gripping the wire Without moving the plunger axially when the member moves through a certain distance in one direction, the said connection being made to retract the plunger into the cylinder for ejecting the wire when the movement of the member is reversed and continued in the opposite direction.

5. In a box strapping machine, a wire holder comprising a cylinder with a slanting upper end, a plungermovable therein, spring means causing the plunger to normally project beyond the cylinder, the projecting end being formed with an endwise slot for receiving a wire therein, a member movable longitudinally on the plunger and a connection between the member and the plunger causing the plunger to turn for gripping the wire without moving the plunger axially when the member moves through a certain distance in one direction, the said connection being made to retract the plunger into the cylinder for ejecting the wire when the movement of the member is reversed and continued in the opposite direction.

6. In a box strapping machine, a retractible post, means for securing a wire thereto and a collar snugly encircling the post for pushing off the wire when the post is retracted intothe collar.

'7. In combination, an arm arranged in substantially upright position and having its lower end swingably supported, an element slidable on the arm and extendible therefrom, an angularly-disposed lever having a pivot supporting the same intermediate its ends, a substantially horizontal cylinder having a pivoted connection with the upper lever end, a rod swingably connected to the arm having a piston within the cylinder, means for moving the piston relative to the cylinder in either'direction, a link connecting the lower lever end with the slidable element, and a wire-feeder on the slidable element.

8. In a box strapping machine, means for supporting a box with one end projecting beyond the support, a swingably supported extensible member normally disposed entirely below the box when in a position of rest and movable across the face of the projecting box end in a plane parallel thereto, means for guiding the free end of the extensible member in a path corresponding substantially to the shape of the box and a feeder for a strand of wire revolvable in the free end of the member and projecting over the box so as to feed the wire therearound.

9. In combination, an endwise extensible member, means pivoting one end thereof for swinging of the member in a lateral plane, the member being extensible in the plane defined by the swinging of the member, means for actuating the member to cause its free end to describe the path of a loop, and means for feeding a tying strand from said free end during the describing of the loop.

10. In combination, an endwise extensible member, means pivoting one end thereof for swinging of the member in a lateral plane, the member being extensible in the plane defined by the swinging of the member, means for actuating themember to cause its free end to describe the path of a loop, the later means including a guide member for controlling the shape of the loop, and means for feeding a tying strand from said free end during the describing of the loop.

11. In a box strapping machine, means for supporting a box with one end projecting beyond the support and means for guiding a wire around the projecting box end, the latter means including an endwise extensible member mounted for lateral swinging across the face of the projecting box end and an exchangeable guide member cooperating with the' extensible member for controlling the path followed by the wire,

12. In a box strapping machine, a rod-like holder having a pair of spaced prongs, mechanical means for introducing a wire between the prongs from one side of the holder, and means for turning the wire holder axially, whereby the wire is Zvrapped relative to the holder and locked in posiion.

13. In a box strapping machine, an endwise extensible member having one end thereof pivotally supported, means for guiding the free end of the member to describe the path of a loop corresponding substantially to the outline of a box, and a wire feeding spout projecting from the free end of the member to feed a wire around the box, the spout being revolvable in the member for turning on an axis paralleling the axis of the pivotal support of the member and having means for yieldingly holding the spout in a predetermined position. g

14. In a box strapping machine, a rotatable post having a slot therein, a movable member having a wire projecting therefrom, the slot being alignable with the projecting wire when the post is turned into a predetermined position, means for moving the member toward the post, whereby the wire is made toenter the slot, and means for turning the post for fastening the wire to the same, the post having a cut-away portion to allow the movable member to pass from one side of the post to the other after the post has been turned for fastening the wire thereto.

15. In combination, an arm arranged in substantially upright position and having its lower end swingably supported, an element slidable on the arm and extendible therefrom, an angularlydisposed lever having a pivot supporting the same intermediate its ends, a substantially horizontal link connecting the upper lever end with the arm. a second link connecting the lower lever end with the slidable element, a wire-feeder on the slidable element, means for extending and contracting the first-named link to move the element relative to the arm and to swing the latter on its pivot, and means for guiding the wire-feeder in a looped path.

16. In a box strapping machine, means for supporting a box, means for anchoring the end of a wire, a swingably mounted arm and an element slidable relative thereto, the slidable element having a wire-feeder thereon for looping a wire around the box, a guide plate having an endless groove, a roller on the slidable element to move the wire-feeder in the path of a loop when the roller travels around the groove, means for moving the roller around the groove, an extension groove communicating with the endless groove to receive the roller, and means for arresting feeding of the'wire from the wire-feeder when the roller enters the extension groove, whereby the looped wire is tensioned around the box.

17 In a box strapping machine, means for supporting a box, means for anchoring the end of a wire, a swingably mounted arm and an element slidable relative thereto, the slidable element having a wire-feeder thereon for looping a wire around the box, a guide plate having an endless groove, a roller on the slidable element to move the wire-feeder in the path of a loop when the roller travels around the groove, means for moving the roller around the groove, an extension groove communicating with the endless groove to receive the roller, means for aesting feeding of the wire from the wire-feeder when the roller enters the extension groove, whereby the looped Wire is tensioned around the box, and means normally closing the extension groove against entry of the roller.

FREDERICK M. BYL, 

